Field of the Invention
Implements or devices for applying rotational force to a spring.
Description of Related Art
Power tools, using air or electric motors, are commonly used to rapidly turn nuts, bolts, and screws. However, these tools as currently marketed are not designed to apply twisting (torsion) forces to the springs of a counterbalancing garage door mechanism.
Most of the foregoing door mechanisms utilize long coil springs that are placed under a rotational or torsion force to apply a lifting force to the door. The springs are concentrically positioned about a rotatable shaft mounted on fixed supports. The shaft carries drums accommodating cables, and these cables are attached to the bottom panel of the door so that when the drums are rotated, a lifting force will be applied to the door. The lifting force is transmitted from the torsion springs to the drums by the shaft. The springs must be anchored on one end, and the free end connected to a winding cone on the shaft, and the winding cone is then rotated to “load” the springs; e.g., place the springs under torsion force. When the torsion force is “loaded,” the winding cone is then connected to the shaft by a mechanical means, and the system is ready.
Previously, long steel rods have been used to insert into open bores in the winding cone to rotate the winding cone and “load” the spring. The amount of force that can be applied to the spring is limited by the strength of the person using the rods, since rotating the winding cone in this manner is a manual operation. The procedure requires a considerable amount of time and can be dangerous as the spring becomes loaded with considerable force.
While there have been other devices patented to introduce temporary mechanical power to “load” these door springs, such designs required some setup work over the shaft or at the winding cone for each spring, before they could begin to “load” the spring. Still other devices are for permanently installed mechanisms, increasing both the installation and subsequent repair costs.
The current invention is safer to use than a manual procedure, and eliminates the setup times typical of past devices.
It would be further desirable to to provide a device with relatively few moving parts to wear out, eliminating the increased costs associated with the permanently installed mechanisms.